input.is-invalid {border-color: #dc3545;padding-right: calc(1.5em + 0.75rem);background-image: url('data:image/svg+xml,...');background-repeat: no-repeat;background-position: right calc(0.375em + 0.1875rem) center;background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);}textarea.is-invalid {border-color: #dc3545;padding-right: calc(1.5em + 0.75rem);background-image: url('data:image/svg+xml,...');background-repeat: no-repeat;background-position: right calc(0.375em + 0.1875rem) center;background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);}.invalid-feedback {display: block;color: #dc3545;}input.is-invalid:focus {border-color: #dc3545;box-shadow: 0 0 0 0.2rem rgba(220, 53, 69, 0.25);}.overlay {position: fixed;top: 0;left: 0;width: 100%;height: 100%;background: rgba(0, 0, 0, 0.5);display: flex;justify-content: center;align-items: center;visibility: hidden;opacity: 0;text-align: center;padding: 20px 40px;box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);z-index: 999;transition: opacity 0.5s ease-in-out, visibility 0.5s ease-in-out;}.small-alert {background-color: #d4edda;border: 1px solid #c3e6cb;color: #155724;padding: 20px 40px;border-radius: 5px;font-size: 18px;text-align: center;box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);}.overlay.show {visibility: visible;opacity: 1;}.overlay.fade-out {opacity: 0;visibility: hidden;}